-er a-a a-b a-t aaa aab aae aak aar aat aax ab- aba abb abe abk abr abt abx aea aeb aee aek aer aet aex aka akb ake akk akr ar- ara arb are ark arr art arx at- ata atb ate atr att atx ax- axa axe axk axr axt axx baa bab bae bak bar bat bax bba bbb bbe bbk bbr bbt bbx be- bea beb bee bek ber bet bex bka bkb bke bkk bkr bkt bkx bra brb bre brk brr brt brx bta btb bte btk btr btt btx bxb bxx eaa eab eae eak ear eat eax eba ebb ebe ebk ebr ebt ebx eea eeb eee eek eer eet eex eka ekb eke ekr ekt era erb ere erk err ert eta etb ete etk etr ett etx ex- exa exe exr ext exx k-t ka- kaa kab kae kak kar kat kax kba kbb kbe kbk kbr kbx ke- kea keb kee kek ker ket kex kkb kke kkk kkr kkt kra krk krr krt kta ktb kte ktk ktr ktt ra- raa rab rae rak rar rat rax rba rbb rbe rbk rbr rbt rbx re- rea reb ree rek rer ret rex rkb rke rkk rkt rra rrb rrk rrr rrt rta rtb rte rtk rtr rtt rtx rxr t-x taa tab tae tak tar tat tax tba tbb tbe tbk tbr tbt te- tea teb tee tek ter tet tex tka tkb tke tkk tkr tkt tra trb tre trk trr trt trx tta ttb tte ttk ttr ttt ttx txe txk txt xaa xak xar xat xbe xbr xbx xee xer xet xex xkb xke xrt xrx xtr xtx xxx

a-ak a-be aaaa aaab aaae aaar aaba aabb aabt aaea aaka aake aara aare aart aata aatk aatt abaa abab abae abak abar abat abax abb- abba abbb abbe abbr abbt abee aber abet abra abta aeer aeka aer- aera aeta aetr aett aetx akaa akae akar akee aker akka akr- akra akre akte arab arae arak arar arat arax arba arbe area aree arek aret arex arka arke arr- arra arre arrk arrr arrt arta arte artr artx at-t at-x ataa atab atae atak atar atat atax atea atee ater atex atka atkt atra atre atrk atrx atta atte attr axar axat axer ba-x baaa baak baar baat baba babb babe babr baek baer bak- baka bake bakr bakt bar- bara barb bare bark barr bart barx bata bate batt baxt bbbb bbeb bbet beak bear beat beba bebb bebe beeb beek beer beet beka beke bera bere berk berr bert beta bete bett brab brae brak brat brax brea breb bree brek brer bret brex brka brkb brrr btaa btek btex btrt bttb eaba eara earb eare eart eata eate ebba ebbr eber eeea eeee eeka eeke eera eeta eete eext eka- ekab ekeb ekek eker eket ekka ekta er-x erat erba erbb erbe ereb erer eret erke erra erre erta etak etat etbr etee eter etka etra etre etta ette exa- exer exrx exta exte extr kaaa kaab kaak kaar kaat kaba kabb kabe kabr kaer kaet kaka kake kakk kakt kakx kara karb kare kark karr kart karx kat- kata katb kate katk katr katt katx kaxa kaxe kbaa kbab kbae kbak kbar kbat kbba kbbb kbbe kbbk kbbr kbbt kbeb kbee kbek kber kbet kbex kbkb kbkk kbkr kbra kbrb kbre kbrk kbrt kbrx kbta kbtb kbte kbtk kbtr kbtt kbxb kbxr kbxt kbxx kea- keak kear keat keba kebb kebe kebr kebt keek keer keet keka kekb keke ker- kera kerb kere kerk kerr kert kerx ket- keta kete ketk ketr kett ketx kexa kexb kexx kkaa kkar kkat kkba kkbb kkbe kkbr kkbt kkea kkex kkkk kkrb kkre kkrk kkrr kkrt kkrx kktk kktx kkxa kkxk kkxt kkxx krab krae krak krar krat krba krbb krbe krbk krbr krbt krbx krea kreb kree krek kret krex krka krke krkk krkr krkx krrb krre krrk krrr krrt krrx krta krtk krtr krtx krxa krxb krxk krxr krxt krxx ktaa ktae ktak ktar ktat ktba ktbb ktbr ktbt ktea ktee ktek ktex ktkb ktke ktkk ktkr ktkt ktkx ktrb ktre ktrk ktrr ktrt ktrx kttk kttr kttt kttx ktxa ktxb ktxk ktxr ktxt kxaa kxar kxba kxbr kxbt kxbx kxea kxet kxex kxkk kxkt kxkx kxra kxrb kxre kxrk kxrr kxrx kxta kxte kxtk kxtt kxtx kxxe kxxk kxxr kxxt kxxx raab raak raat raba rabb rabe rabk raer raka rake rakk rakt rara rarb rare rark rata rate ratk ratt raxa rbbb rbbr rea- reae reak rear reat reba rebb rebe rebk reeb reek reet reka reke rekt rera rere rert reta rete retr rett rexx rrat rrrr rtee rtex taa- taar taat taba tabb tabe taer taka take takk takt tara tarb tare tark tarr tart tata tatb tate tatr tatt tax- taxa taxe taxt tbar tbrb tbta teak tear teat teba teek teer teet teka teke ter- tera tere terk terr teta tete tetr tett tetx texa text traa trab trae trak trat trax tre- trea tree trek tret trex trra trte trtr ttab ttbb tter tttt txaa txtr xaar xara xare xate xbar xbee xbra xeer xeka xer- xera xert xexe xtar xtea xtra xxxx

-aaa- -tree aaaee aaata aabaa aabba aabra aaker aakre aatxe abaab ababa ababe abaer abaka abake abara abare abate abbar abbat abbet abear abeat abeba abebe abeer abeet abekr abera abere aberr abert abkar abrak abrar abrek abtaa abtar aeaea aebbe aetat aeter aka-e akaba akare akata akbar akera akert aketa akete akker akkra akrak akrar ar-ab araat arab- araba arabe araea arake arara arare arata arate araxa arbab arbar arbat arbee arber arbet arbre areae arear areat areek areet areka areke arere arete arett arexx arkar arkat arrak arrea arret art-x artar artat artax artea artek arter artex ataka atake atara ataxx atbar atbat atear ateat ater- aterr atete atrab atrak atrax atree atrek atrex attak attar attea atter attex attra